Effect of highly hydrophobic plant oil-based monomers on micellization of sodium dodecyl sulfate

Abstract

The effect of highly hydrophobic olive oil-based (OVM) and high oleic soybean oil-based (HO-SBM) acrylic monomers on micellization of sodium dodecyl sulfate (SDS) was examined at different surfactant and monomer concentrations by determining micellar parameters, size and structure, as well as surface tension measurements. The obtained results indicate SDS ability to solubilize sparingly soluble in water plant oil-based monomer (POBM) molecules and facilitate formation of mixed (SDS/POBM) micelles. Surface activity of a surfactant/monomer mixture varies by adding the POBM and is generally higher than for SDS. Comprehensive trends were observed for micellar aggregation number and number of micelle-bound monomer molecules demonstrating that POBM molecules replace SDS counterparts in the mixed micelles. Based on dynamic light scattering measurements (DLS), we hypothesized that incorporation of POBM into the mixed micelles promotes micellar association and formation of 25–30 nm size structures, also detected using transmission electron microscopy (TEM). Practical importance of these findings is the fact that solubilization of POBM by surfactant molecules can have an impact on reaction kinetics and mechanism of emulsion polymerization, as well as affect latex particles formation and, respectively, resulting particle morphology.